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Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c31
1 files changed, 27 insertions, 4 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 42bf89aaf6a5..f9f9e375d7de 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3115,6 +3115,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
long ca_rtt_us = -1L;
struct sk_buff *skb;
u32 pkts_acked = 0;
+ u32 last_in_flight = 0;
bool rtt_update;
int flag = 0;
@@ -3154,6 +3155,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
if (!first_ackt.v64)
first_ackt = last_ackt;
+ last_in_flight = TCP_SKB_CB(skb)->tx.in_flight;
reord = min(pkts_acked, reord);
if (!after(scb->end_seq, tp->high_seq))
flag |= FLAG_ORIG_SACK_ACKED;
@@ -3250,7 +3252,8 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
if (icsk->icsk_ca_ops->pkts_acked) {
struct ack_sample sample = { .pkts_acked = pkts_acked,
- .rtt_us = ca_rtt_us };
+ .rtt_us = ca_rtt_us,
+ .in_flight = last_in_flight };
icsk->icsk_ca_ops->pkts_acked(sk, &sample);
}
@@ -5169,6 +5172,7 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
const struct tcphdr *th, int syn_inerr)
{
struct tcp_sock *tp = tcp_sk(sk);
+ bool rst_seq_match = false;
/* RFC1323: H1. Apply PAWS check first. */
if (tcp_fast_parse_options(skb, th, tp) && tp->rx_opt.saw_tstamp &&
@@ -5205,13 +5209,32 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
/* Step 2: check RST bit */
if (th->rst) {
- /* RFC 5961 3.2 :
- * If sequence number exactly matches RCV.NXT, then
+ /* RFC 5961 3.2 (extend to match against SACK too if available):
+ * If seq num matches RCV.NXT or the right-most SACK block,
+ * then
* RESET the connection
* else
* Send a challenge ACK
*/
- if (TCP_SKB_CB(skb)->seq == tp->rcv_nxt)
+ if (TCP_SKB_CB(skb)->seq == tp->rcv_nxt) {
+ rst_seq_match = true;
+ } else if (tcp_is_sack(tp) && tp->rx_opt.num_sacks > 0) {
+ struct tcp_sack_block *sp = &tp->selective_acks[0];
+ int max_sack = sp[0].end_seq;
+ int this_sack;
+
+ for (this_sack = 1; this_sack < tp->rx_opt.num_sacks;
+ ++this_sack) {
+ max_sack = after(sp[this_sack].end_seq,
+ max_sack) ?
+ sp[this_sack].end_seq : max_sack;
+ }
+
+ if (TCP_SKB_CB(skb)->seq == max_sack)
+ rst_seq_match = true;
+ }
+
+ if (rst_seq_match)
tcp_reset(sk);
else
tcp_send_challenge_ack(sk, skb);